Maharashtra Board Class 8 Man Made Materials ,This page includes Fill in the Blanks, TB Q/A, as well as Extra Questions and Answers from the chapter.
Try to find it.
- Plastic shows …… property, hence it can be moulded to any shape.
- Motor cars are coated with …….
- Thermocol melts at …… ºC.
- …… glass dissolves in water.
Solution
- Plastic shows plasticity property, hence it can be moulded to any shape.
- Motor cars are coated with paint.
- Thermocol melts at more than 100 ºC.
- Alkali silicate glass dissolves in water.
Who is my partner?
‘A’ column ‘B’ column
- Lead glass i. Plates
- Bakelite ii. Mattresses
- Thermocol iii. Electric bulb
- Optic glass iv. Electric switch
- Polypropylene v. Lens
Solution
- Lead glass – iii. Electric bulb
- Bakelite – iv. Electric switch
- Thermocol – i. Plates
- Optic glass – v. Lens
- Polypropylene – ii. Mattresses
Answer the following.
Thermocol is produced from which material?
Thermocol is produced from a complex material called polystyrene.
Write uses of PVC.
Uses of PVC (Polyvinyl Chloride):
- Bottles
- Raincoat
- Pipes
- Handbags
- Shoes
- Electric cable insulation
- Furniture
- Ropes
- Toys, etc.
Write the natural or manmade raw material of the following items.
Mattress, glass vessel, bangle, chair, gunny bag, broom, knife, pen.
Natural or manmade raw material for the following items:
- Mattress: Polypropylene (manmade)
- Glass vessel: Sand (natural)
- Bangle: Plastic (manmade)
- Chair: Plastic or Wood (manmade or natural)
- Gunny bag: Jute (natural)
- Broom: Grass or Plastic (natural or manmade)
- Knife: Metal (manmade)
- Pen: Plastic or Metal (manmade)
Which are the main ingredients of glass?
The main ingredients of glass are sand (silicon dioxide), soda, lime, and sometimes small quantities of magnesium oxide.
How the plastic is produced?
Plastic is produced through a process called polymerization. It involves the synthesis of organic polymers, which are large molecules made up of repeating units called monomers. The raw materials for plastic production are typically derived from petrochemicals, and the process involves various chemical reactions to form the desired plastic polymer.
Distinguish between
a.Manmade material and natural material
| Manmade Material | Natural Material |
| Produced in factories or laboratories | Found in nature, not significantly altered by human processes |
| Result of human intervention and processing | Formed through natural geological or biological processes |
| Plastic, synthetic fabrics, metals, ceramics | Wood, cotton, leather, stone, minerals |
| Can be extensively modified and engineered | Limited modification without human intervention |
| Depends on human actions, technology, and industry | Independent of human intervention, occurs naturally |
b.Thermoplastic and thermosetting plastic
| Thermoplastic | Thermosetting Plastic |
| Softens and becomes pliable when heated | Sets irreversibly when heated |
| Can be molded and reshaped multiple times | Sets into a rigid form upon initial molding |
| Can be recycled and reused multiple times | Usually cannot be recycled |
| Polyethylene, PVC, Polypropylene | Bakelite, Melamine, Epoxy resin |
| Packaging, toys, containers, pipes | Electric switches, cookware handles, composites |
| Sensitive to heat, may deform at high temperatures | Resistant to high temperatures, retains shape when heated |
| May be affected by certain chemicals | Chemically stable, resistant to many chemicals |
